KR100332832B1 - Squirrel rotor using composite material and its manufacturing method - Google Patents

Abstract

The present invention provides a cage rotor and a method for manufacturing the same using a composite material which can improve the quality of the product by high-speed and ultra-precision processing by lightening the rotor and cooling the heat using fiber-reinforced composite materials and heat pipes. There is a purpose.

The present invention for achieving the above object, the composite pipe 22 is made of a composite material coupled to the circumference of the rotary shaft 21, a squirrel cage conductor coupled to the circumference of the composite pipe 22 23). In addition, a heat pipe 25 for cooling heat is coupled to the slot 24 of the cage conductor 23, and the composite pipe 22 has powder that adheres well to a magnet so as to improve the performance of the electric motor. It is preferable that it contains additionally. In addition, the composite pipe 22, the thick conductor 23, and the heat pipe 25 are preferably joined by an epoxy adhesive or a resin 27 contained in the composite pipe 22, respectively.

Description

Squirrel rotor using composite material and its manufacturing method

The present invention relates to a cage rotor of an induction motor, and more particularly, to a cage rotor using a fiber-reinforced composite material. The invention also relates to a method of manufacturing such a cage rotor.

With the development of aerospace and automotive industries, the need for materials with low mass and density but good strength and rigidity is increasing. As a result, researches on fiber-reinforced composite materials having higher strength and stiffness but lower specific gravity than existing metal materials are being actively conducted, and fiber-reinforced composite materials are increasingly used in various industries. There is a situation.

Squirrel cage rotors according to the prior art are shown in FIGS. 1 and 2.

As shown in Figs. 1 and 2, the cage rotor according to the prior art includes a rotating shaft (11). The rotor iron core 12 is disposed around the rotary shaft 11. This rotor iron core 12 is formed by stacking a plurality of circular plates 14 in which a plurality of slot grooves 13 are formed on a circumference. On the surface of the iron core 12 thus formed, a plurality of slots 15 are formed by the slot grooves 13 formed in the circular plate 14. At this time, the slot 15 is formed along the rotation axis (11). The slot grooves 13 of the iron cores 12 arranged in this way serve to generate an induced current from a coil wound on a stator, and each of the conductor rods 16 used to fix the circular plates 14 is inserted therein. It is. The conductor rods 16 inserted in this way are short-circuited by a short ring 17 located at both ends of the rotor iron core 12.

Since the squirrel rotor of the prior art configured as described above is manufactured in a combination structure of a rotor iron core and a conductor rod using steel materials such as silicon steel sheet and cast iron, the rotor has a heavy weight. That is, high torque is required when driving the motor, and when the motor rotates at a high speed, it is influenced by centrifugal force and inertia force proportional to the mass of the rotor, causing large stress inside the motor, resulting in excessive deformation. Such deformation has a great effect on the quality of the product to be processed when high-speed, ultra-precision operation is required, and as the inertial force increases, it becomes difficult to control the rotor.

In addition, larger and higher speed motors have a problem that the rotor is affected by excessive heat deformation due to induction heat generated by current induced in the rotor and heat generated in the rotor when the motor rotates at high speed.

Therefore, the present invention has been made to solve the problems of the prior art as described above, by using a composite material that can improve the quality of the product at high speed and ultra precision processing by lightening the rotor using a fiber-reinforced composite material An object of the present invention is to provide a cage rotor and a manufacturing method thereof.

In addition, another object of the present invention is to provide a heat pipe (heat pipe) by using a composite material that can reduce the heat generated by the induction heat generated by the current induced in the rotor and the motor rotates at high speed To provide the former.

1 is a perspective view of a cage rotor according to the prior art,

FIG. 2 is a side view of a circular plate having a plurality of slot grooves constituting the cage rotor shown in FIG. 1;

3 is a perspective view for explaining the components of the cage rotor using the composite material according to the first embodiment of the present invention,

4 is a cross-sectional view taken along line A-A of the cage rotor using the composite material shown in FIG. 3;

5 is a cross-sectional view of a cage rotor using a composite material according to a second embodiment of the present invention,

6 is a cross-sectional view of a cage rotor using a composite material according to a third embodiment of the present invention,

FIG. 7 is a perspective view illustrating a manufacturing method of a cage conductor which is an important part of a cage rotor using the composite material shown in FIG. 3;

FIG. 8 is a perspective view for explaining a relationship with a mold used to mold a cage rotor using the composite material shown in FIG. 6; FIG.

Explanation of symbols on the main parts of the drawings

20: cage rotor 21: rotation axis

22: round pipe 23: cage conductor

24: slot 25: heat pipe

26: adhesive 27: resin

The present invention for achieving the object as described above includes a composite pipe coupled to the periphery of the rotation axis made of a composite material, and a squirrel cage conductor coupled to the periphery of the composite pipe.

In addition, it is preferable that a heat pipe for cooling heat is coupled to the slot of the concentrated conductor of the present invention, and the composite pipe additionally contains powder that adheres well to the magnet so as to improve the performance of the electric motor. Do. In addition, the composite pipe, the thick conductor and the heat pipe of the present invention are preferably joined by an epoxy adhesive or a resin contained in the composite pipe.

In addition, the present invention for achieving the object as described above, manufacturing a composite pipe that can be disposed around the rotation axis, curing the composite pipe, and disposed around the composite pipe Fabricating the squirrel conductor into a high conductor material, coupling the composite pipe and the squirrel conductor, and coupling a rotating shaft to the composite pipe. In addition, the present invention additionally includes the step of coupling a heat pipe for cooling the heat in the slot of the concentrated conductor, and after heating the concentrated conductor and thermal fitting (thermal fitting) to join the composite pipe and the concentrated conductor Is good.

In addition, the present invention for achieving the object as described above, the step of manufacturing an uncured composite pipe that can be disposed around the axis of rotation, and the dense conductor disposed around the composite pipe is a high conductor material Coupling the composite pipe and the dense conductor by inserting the composite pipe into a dense conductor and curing in an autoclave, and coupling a rotating shaft to the composite pipe. . In addition, the present invention preferably additionally arranges heat pipes for cooling heat in slots of the dense conductors, and hardens and bonds them in an autoclave.

In the following, with reference to the accompanying drawings, preferred embodiments of the cage rotor and the manufacturing method using a composite material according to the present invention will be described in detail.

[First Embodiment]

In the drawings, FIG. 3 is a perspective view illustrating components of the squirrel rotor using the composite material according to the first embodiment of the present invention, and FIG. 4 is a line AA of the squirrel rotor using the composite material shown in FIG. 3. 7 is a cross-sectional view taken along the line, and FIG. 7 is a perspective view illustrating a method of manufacturing a cage conductor, which is an important part of a cage rotor using the composite material illustrated in FIG. 3.

As shown in Figures 3 and 4, the cage rotor 20 using the composite material of the present invention is a rotary shaft 21, and the circular pipe 22 is disposed around the rotary shaft 21 and made of a composite material and And a heat pipe 25 disposed in the slot 24 formed in the cage conductor 23, and the heat conductor 25 disposed around the circular pipe 22.

Here, the circular pipe 22 cuts and laminates a plurality of flat plate-like composite materials in a desired direction, and then manufactures the circular pipe 22 in a circular shape using a mandrel coated with a release material. Once the shape is formed by the mandrel, it is placed in an autoclave and cured with a suitable curing cycle. Then, a circular pipe 22 formed of a composite material is formed. At this time, the circular pipe 22 is preferably manufactured by adding a powder that adheres to the magnet, such as fine iron powder, to the composite material to improve the performance of the electric motor.

Further, a circumferential conductor 23 for generating an induced current from a coil wound around a stator is disposed around the circular pipe 22 made of a composite material. This squirrel conductor 23 is made of a thin pipe with high electrical conductivity, such as copper or aluminum. At this time, the cage conductor 23 is manufactured by cutting the conductive pipe using the processing apparatus 31 as shown in FIG. 7 to form a plurality of elongated rod-shaped slots 24. At this time, the slot 24 is formed along the axial direction, and a plurality of slots 24 are formed at predetermined intervals in the circumferential direction. Thus, the processing apparatus 31 which forms the slot 24 is an end mill, an electric wire for electric discharge machining, a laser processing machine, etc.

The slot 24 of the cage conductor 23 thus formed may be machined to have a constant angle with respect to the axial direction of the pipe. In addition, in order to process a thin pipe made of copper or aluminum having a relatively low rigidity into a desired shape, a flexible material having the same dimensions as the inner diameter of the pipe may be inserted into the pipe, and then the cutting may be performed to remove the internal flexible material.

The heat pipe 25 for cooling the heat generated when the rotor rotates at high speed is fixed to the slot 24 of the cage conductor 23 thus formed. At this time, the heat pipe 25 is firmly fixed by the adhesive or the surplus resin produced during curing. Here, the heat pipe 25 is a cooling device in which an operating medium such as ammonia, methanol, freon, etc. in a vacuum-formed pipe transfers heat to a heat sink far from a heat source by repeating an isothermal change cycle between steam and gas phase. Say. That is, when heat is applied to the heat pipe 25, rapid heat transfer proceeds with the heat of vaporization due to the phase change of the fluid in the heat pipe 25 into the gas. That is, the gas which has moved to the opposite side of the relatively low temperature condenses into the fluid and cools the heat by dissipating the heat of absorption during the evaporation process.

In the following, a method for manufacturing a cage rotor using the composite material of the present invention configured as described above will be described.

First, the circular pipe 22 and the rotating shaft 21 formed through the process as described above are combined. Then, an adhesive 26 such as epoxy is applied around the circular pipe 22, and then the dense conductor 23 is inserted into the circular pipe 22 and joined. At this time, it is used that the cage conductor 23 has an inner diameter slightly larger than the outer diameter of the circular pipe 22. Then, the heat pipe 25 is fixed to the slot 24 of the cage conductor 23 using the adhesive 26. In this way, a cage rotor using a composite material is produced.

Second Embodiment

The cage rotor using the composite material according to the second embodiment of the present invention is identical to the components of the first embodiment except that it is manufactured by thermal fitting. Therefore, the description of the components will be omitted here, and only the manufacturing method thereof will be described.

5 is a cross-sectional view of a cage rotor using a composite material according to a second embodiment of the present invention.

As shown in FIG. 5, the circular pipe 22 and the rotation shaft 21 are coupled. Then, the cage conductor 23 is heated and then shrinked around the circular pipe 22. In this way, the cage conductor 23 is firmly fixed to the circumference of the circular pipe 22. At this time, the cage conductor 23 is one having an inner diameter slightly smaller than the outer diameter of the circular pipe 22. Then, the heat pipe 25 is fixed to the slot 24 of the cage conductor 23 using the adhesive 26. In this way, a cage rotor using a composite material is produced.

Third Embodiment

The cage rotor using the composite material according to the third embodiment of the present invention is manufactured by first curing the circular pipe, the cage conductor, and the heat pipe first in place and then simultaneously curing them without first curing the circular pipe. It is the same as the component of one Embodiment. Therefore, the description of the components will be omitted here, and only the manufacturing method thereof will be described.

6 is a cross-sectional view of a cage rotor using a composite material according to a third embodiment of the present invention, Figure 8 is a mold used to mold a cage rotor using the composite material shown in FIG. A perspective view for explaining the relationship.

The co-curing method used here includes a manufacturing method using a prepreg and a manufacturing method using a mold. First, a manufacturing method using a prepreg will be described.

As shown in FIG. 6, after placing the squirrel conductor 23 around the circular pipe 22 wound on the mandrel and not cured, the heat pipes 25 are respectively placed in the slots 24 of the squirrel conductor 23. To place. Then, the surface of the cage conductor 23 and the heat pipe 25 is coated with a prepreg. This is then placed in an autoclave and cured with a suitable curing cycle. Then, the resin 27 contained in the prepreg and the circular pipe 25 respectively melts to fill the gap between the circular pipe 22 and the dense conductor 23 and the slot 24. Through this process, the circular pipe 22, the cage conductor 23, and the heat pipe 25 are combined. Then, the prepreg hardened on the surface of the cage conductor 23 is ground to process the surface of the cage conductor 23 to be exposed to the outside. When this operation is completed, the mandrel is separated from the circular pipe 22 and the rotary shaft 21 is inserted thereinto engage. In this way, a cage rotor using a composite material is produced. In this co-curing method, the mandrel may be removed from the uncured round pipe 22 and a vacuum bag may be inserted therein to co-cur in the autoclave.

The prepreg used herein refers to a composite material hardened to some extent by impregnating carbon fiber, glass fiber, and various fibers with phenol resin, epoxy resin, polyester resin, polyamide resin, and the like.

Hereinafter, a manufacturing method using a mold will be described.

As shown in FIG. 8, first, two steel blocks 41 are polished by grinding operation, one surface each to face each other. Thereafter, through drilling and boring operations, holes 42 having the same dimensions as the outer diameters of the cage conductors 23 are formed. At this time, the right and left ends of the hole 42 of the steel block 41 is processed by the bolt hole 43 and the pinhole 44 penetrating the inner surface of the steel block 41, the exact position of the two blocks when forming the components of the cage rotor To facilitate adjustment. In addition, a mold (not shown) such as Teflon is applied to the inside of the hole 42 to smoothly demould the components of the cage rotor.

When the mold is completed in this way, as shown in FIG. 6, the squirrel conductor 23 is disposed around the circular pipe 22 wound by the mandrel and not cured, and then inserted into the slot 24 of the squirrel conductor 23. The heat pipes 25 are disposed respectively. Then, after removing the mandrel from the circular pipe 22, it is accurately placed in the hole 42 of the mold using the guide pin 45 and tightened with the bolt 46 tightly.

Then, the outside of the mold and the inside of the circular pipe 22 are wrapped with a vacuum bag made of nylon or the like. Thereafter, the mold is placed in an autoclave that can control temperature and pressure, and a vacuum is applied inside the vacuum bag and pressure is applied outside the vacuum bag. Then, the resin 27 contained in the circular pipe 25 fills the gap between the circular pipe 22 and the dense conductor 23 and the slot 24. Through this process, the circular pipe 22, the cage conductor 23, and the heat pipe 25 are combined. Then, the rotary shaft 21 is inserted into the circular pipe 22 to be coupled. In this way, a cage rotor using a composite material is produced.

Although the above-described embodiments have described the squirrel-type rotor using a rotating shaft of steel material that has been used in the past, the squirrel-cage rotation using a composite hollow rotating shaft having a hollow circular cross section manufactured separately instead of the rotating shaft of steel materials The former can also be produced.

The cage rotor using the composite material of the present invention described above has the advantage that the mass is light because it uses a polymer matrix fiber reinforced composite material having a low density of less than 1/4 compared to the conventional steel material.

In addition, since the squirrel rotor using the composite material of the present invention is light in weight, it does not require high driving torque, reduces vibration generated by the eccentric mass, and reduces the centrifugal force and stress generated therein during rotation. When the motor rotates at high speed, the inertia is reduced to improve the product quality.

In addition, since the squirrel rotor using the composite material of the present invention has a heat pipe, there is an effect of reducing the heat deformation caused by the induced heat generated by the current induced in the rotor and the heat generated when the motor rotates at high speed.

The technical idea of the cage-shaped rotor and the manufacturing method using the fiber-reinforced composite material according to the present invention has been described above with the accompanying drawings, but this is illustrative of the best embodiment of the present invention to limit the present invention no.

Claims (8)

In a squirrel cage rotor in which the rotating shaft rotates when the current flows through the stator coil of the induction motor, A composite pipe coupled to the circumference of the rotating shaft, the composite pipe including a plurality of composite material layers, the composite material layer containing powder to which magnets adhere well; A squirrel cage conductor coupled to the periphery of the composite pipe and having a plurality of slots formed along a circumference thereof; Squirrel rotor using a composite material comprising a; heat pipe (heat pipe) coupled to the slot formed in the squirrel conductor. The cage rotor of claim 1, wherein the composite pipe, the cage conductor, and the heat pipe are each bonded with an epoxy adhesive. The cage rotor according to claim 1 or 2, wherein the composite pipe, the cage conductor, and the heat pipe are respectively joined by a resin contained in the composite pipe. In the manufacturing method of a squirrel cage rotor that is magnetized when the current flows through the stator coil of the induction motor rotates, Fabricating a composite pipe that can be disposed around the axis of rotation; Curing the composite pipe; Fabricating a squirrel cage conductor disposed around the composite pipe from a high conductor material; Coupling the composite pipe and the squirrel conductor; The method of manufacturing a cage rotor using a composite material, characterized in that it comprises the step of coupling the rotating shaft to the composite pipe. The method of claim 4, further comprising coupling a heat pipe for cooling heat to the slot of the cage conductor. 6. The method of claim 4 or 5, wherein the composite pipe and the concentrated conductor are joined by heating and heating the caged conductors, followed by thermal fitting. In the manufacturing method of a squirrel cage rotor that is magnetized when the current flows through the stator coil of the induction motor rotates, Manufacturing an uncured composite pipe that can be disposed around the axis of rotation; Fabricating a squirrel cage conductor disposed around the composite pipe from a high conductor material; Inserting the composite pipe into the cage conductor and curing in an autoclave to join the composite pipe and the cage conductor, The method of manufacturing a cage rotor using a composite material, characterized in that it comprises the step of coupling the rotating shaft to the composite pipe. 8. The method according to claim 7, wherein a heat pipe for cooling heat is additionally disposed in the slot of the cage conductor and cured in an autoclave to bond.